High-Speed All-Optical Sampling Based on Nonlinear Polarization Rotation in a Semiconductor Optical Amplifier

A novel all-optical sampling based on nonlinear polarization rotation in a semiconductor optical amplifier is presented. An analog optical signal and an optical pulses train are injected into semiconductor optical amplifier simultaneously, and the analog light modulates the output optical pulse through controlling the rotated angle of nonlinear polarization rotation of the optical pulse. Therefore, the sampling signals are delivered from the analog light to the optical clock pulses. The theoretical model is built up with polarization-dependent rate-equations. The experimental results at 40 GS/s demonstrate the feasibility of our proposed approach.